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6c32117963
Add SNP-specific hooks to the unaccepted memory support in the boot path (__accept_memory()) and the core kernel (accept_memory()) in order to support booting SNP guests when unaccepted memory is present. Without this support, SNP guests will fail to boot and/or panic() when unaccepted memory is present in the EFI memory map. The process of accepting memory under SNP involves invoking the hypervisor to perform a page state change for the page to private memory and then issuing a PVALIDATE instruction to accept the page. Since the boot path and the core kernel paths perform similar operations, move the pvalidate_pages() and vmgexit_psc() functions into sev-shared.c to avoid code duplication. Create the new header file arch/x86/boot/compressed/sev.h because adding the function declaration to any of the existing SEV related header files pulls in too many other header files, causing the build to fail. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/a52fa69f460fd1876d70074b20ad68210dfc31dd.1686063086.git.thomas.lendacky@amd.com
87 lines
2.0 KiB
C
87 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include "error.h"
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#include "misc.h"
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#include "tdx.h"
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#include "sev.h"
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#include <asm/shared/tdx.h>
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/*
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* accept_memory() and process_unaccepted_memory() called from EFI stub which
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* runs before decompresser and its early_tdx_detect().
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*
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* Enumerate TDX directly from the early users.
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*/
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static bool early_is_tdx_guest(void)
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{
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static bool once;
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static bool is_tdx;
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if (!IS_ENABLED(CONFIG_INTEL_TDX_GUEST))
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return false;
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if (!once) {
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u32 eax, sig[3];
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cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax,
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&sig[0], &sig[2], &sig[1]);
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is_tdx = !memcmp(TDX_IDENT, sig, sizeof(sig));
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once = true;
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}
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return is_tdx;
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}
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void arch_accept_memory(phys_addr_t start, phys_addr_t end)
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{
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/* Platform-specific memory-acceptance call goes here */
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if (early_is_tdx_guest()) {
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if (!tdx_accept_memory(start, end))
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panic("TDX: Failed to accept memory\n");
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} else if (sev_snp_enabled()) {
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snp_accept_memory(start, end);
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} else {
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error("Cannot accept memory: unknown platform\n");
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}
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}
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bool init_unaccepted_memory(void)
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{
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guid_t guid = LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID;
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struct efi_unaccepted_memory *table;
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unsigned long cfg_table_pa;
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unsigned int cfg_table_len;
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enum efi_type et;
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int ret;
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et = efi_get_type(boot_params);
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if (et == EFI_TYPE_NONE)
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return false;
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ret = efi_get_conf_table(boot_params, &cfg_table_pa, &cfg_table_len);
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if (ret) {
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warn("EFI config table not found.");
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return false;
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}
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table = (void *)efi_find_vendor_table(boot_params, cfg_table_pa,
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cfg_table_len, guid);
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if (!table)
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return false;
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if (table->version != 1)
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error("Unknown version of unaccepted memory table\n");
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/*
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* In many cases unaccepted_table is already set by EFI stub, but it
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* has to be initialized again to cover cases when the table is not
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* allocated by EFI stub or EFI stub copied the kernel image with
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* efi_relocate_kernel() before the variable is set.
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*
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* It must be initialized before the first usage of accept_memory().
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*/
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unaccepted_table = table;
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return true;
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}
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